This is something I have a need of quite frequently.
“I’m working on a document, creating symbols, then realizing that symbol x/y should be part of the main library”. There used to be a plugin that did this, but is no longer supported.
Hey Pontus!
Thanks for the input and feedback. This is indeed a highly requested feature, and our team is aware of the need. If you have any extra things or feedback related to how you’d like to see this feature work, we’ll be happy to also pass them along to the team!
Hi Pontus 
You can still do this with a couple of plugins: if you need to move Text and layer styles as well as symbols, you’ll need to use Automate Sketch.
But if you only need to move symbols, the Symbol Swapper plugin works really nice!
It takes a few more steps but we can happily provide assistance in productsupport@sketch.com
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